4 types of noise and how you can reduce them

If a tree falls in a forest and nobody is around to hear it… does it make a sound?

This age-old question has been asked for centuries, with mixed interpretations. Some argue that types of noise should only be classified in the physical sense. Millions of people have been there to see trees fall in the forest, and each of them report a sound. Even more, science shows that these trees should make a sound. The compressions and rarefactions that are caused by the tree falling have been shown to emit audio frequencies.

Critics, however, say that even though these things are true, the tree still doesn’t make a sound. They take the philosophical approach by quoting George Berkeley, who says, “to be is to be perceived.” Since nobody is there to hear the tree fall, the event is outside of the human experience, and, consequently, the sound doesn’t exist.

People debate on this argument and will continue to do so for hundreds of years. There may not be a consensus on whether the noise is there or not, but we can agree that the thought experiment shows how important of a role noise plays in helping us understand events. Hikers look up and all around when they hear a ‘whooshing’ noise from a falling tree. This reaction helps keep them safe. The tone of voice coming out of an impassioned person can tell us whether the tears streaming out of our eyes are happy or sad. A blaring car horn lets you know that there’s somebody in your blind spot.

How does sound work?

We hear a million (roughly estimated) different sounds and noises each day. Sound is produced through vibrations traveling through the air. Each sound travels from its source as pressure waves through the air in all directions. These waves have different intensities, pitches, and tones that determine whether the types of noise they make are loud, soft, high, or low. A louder sound has a higher intensity, while a softer sound has a lower intensity. Likewise, sounds with shorter wavelengths have higher pitches, while sounds with longer wavelengths have lower pitches.

All these elements factor into the pressure waves that vibrate our inner ear. Through this vibration, we hear the sensation of sound.

Different types of noise

Noises are categorized in four different ways. The things you hear throughout the day can be either a continuous noise, intermittent noise, impulsive noise, or low frequency noise. By understanding these categorizations, you’ll better understand the measures you can take to protect your hearing.

Continuous noise

Continuous noise comes from objects or machines that run without interruption. These noises are noticeable and happen all around us wherever we go.

In a factory setting, these types of noise emanate from large machinery that works continuously to keep production consistent. In a car, you hear continuous noises from functional objects, like a running engine, or from other things, like the “thrum, thrum, thrum” noises you hear while driving with your windows down.

Intermittent noise

Intermittent noises are infrequent but regular within your daily life. Generally, they come from loud bursts that you notice but are not surprised by.

These types of noise can sometimes have a large impact on your quality of life. For example, if you live next to railroad tracks, you may wake up in the middle of the night to the sounds of a freight train’s horn. Many people pay more money for housing to avoid this type of problem. This can also be shown by the lack of development around airports. Many people don’t want to live in a place where they will hear planes taking off at all hours of the day and night.

​Impulsive noise

An impulsive noise, on the other hand, is not regularly scheduled or recognized. Instead, it is a surprising burst or sound that causes people to look up to see what’s going on.

Frequently, these types of noise are heard in restaurants as waiters or waitresses accidentally drop a pile of dishes on the ground. When this happens, the restaurant generally calms down a little as people look around for the source of the noise. Strangers shouting on the street or loud bursts from construction sites are also considered impulsive noises.

Low frequency noise

A low frequency noise comes from objects around us in everyday life. It is one of the hardest types of noise to reduce, and it makes a seemingly silent room still register sound levels around 30-40 decibels.

In an office setting, this noise comes from a heating or ventilation system. In your home, it comes from the ticking on a grandfather clock. Generally, we don’t even recognize these types of noise unless we direct our attention towards them.

Measuring these types of noise

Measuring how these types of noise impact your hearing can be easy for some and difficult for others. With continuous or low frequency noise, it’s easy to measure the sound levels. Mobile apps like Soundprint give you access to a sound level meter that can be used to tell you if the restaurant you’re dining in is going to damage your ears enough to make you shout for the rest of the night.

For intermittent and impulsive noises, measuring sound levels is trickier. Since the noise levels are not continuously available to detect, you’ll need to keep a sound level meter nearby. Likewise, you’ll need to measure both the sound level and the sound duration to understand its impact on your hearing. A more reliable estimate of the noise level can be found by taking measurements over multiple occurrences and averaging the data. You can also use a personal noise dosimeter to calculate the noise’s Peak values. This measurement is useful and important, as very loud noises can cause hearing damage to your ears, even if you are in an area that is normally quiet.

What if things are too loud?

Different types of noise in your building may become unmanageable at some point. When this happens, there are options you can take to lower the reverberation and volume. One of the best solutions you can use are acoustic panels.

One restaurant near Toledo, OH recognized that different types of noise were damaging their employee’s hearing and lowering the quality of their restaurant.

The restaurant’s manager stated this: “When we do get guest reviews, they are generally positive. However, even sometimes when we do get a very positive review, the one negative point in there will be how noisy the restaurant is. On one hand, it’s tough because we don’t want to apologize for being a busy restaurant. That’s how we want to be, but when this restaurant is jam packed, and every seat in here is full, I can barely hear myself think.”

In order to fix this, the management looked for spots in their building where they could install acoustical panels while maintaining their design aesthetic. Our ceiling panels blended into the restaurants design while providing an inexpensive and transformative solution. In response, the community praised the restaurant by providing them with increased business.

If you recognize that different types of noise are too high in your own building, reach out to one of our reps. They can direct you to an acoustical solution that will be best suited for your space. These solutions will help you manage your sound quality and decrease your noise problems.